Gold colored polyolefin containers

ABSTRACT

A metallic, gold colored polyolefin container prepared from a composition comprising an olefin polymer, a mica-based gold pigment, a mica-based bronze pigment, carbon black, and optionally, a yellow pigment is provided and produced in a grit blasted mold.

This application is a division of application Ser. No. 282,233, filedDec. 9, 1988, which is a division of application Ser. No. 124,804, filedNov. 24, 1987, now U.S. Pat. No. 4,840,997.

BACKGROUND OF THE INVENTION

This invention relates to pigmented olefin polymer compositions.

Conventional color pigments and dyes can be added to polyolefins toproduce a variety of pigmented polyolefins. Pigmented polyolefins areaesthetically pleasing, and thus, the resultant colored polyolefinproduct is more appealing and/or marketable to a consumer. However,pigmented polyolefins are not available in all colors. Metallic coloredpolyolefins, with a consistent pigment distribution, are difficult tomake. The pigments usually used to produce metallic colored polyolefinsare metallic based pigments. The metallic based pigment is difficult toevenly distribute in the polyolefin and the resultant molded productfrequently is not uniform in color.

Molded polyolefin products, both pigmented and unpigmented, can beproduced in grit blasted molds or in polished molds. Polished molds aremore difficult and more expensive to produce, because the interior moldsurface must be smoothed or polished prior to use. If a polished moldneeds to be cleaned during molding operations, the interior of the moldshould be inspected for scratches and, if necessary, re-polished. Hence,polished molds are not as easy to use and maintain as grit blastedmolds. Additionally, imperfections and blemishes in the final product,which can be caused, for example, by air entrapment, are much moreobvious in products produced in a polished mold. Metallic coloredpolyolefins can be molded in a grit blasted mold; however, a glossy,reflective finish is more difficult to obtain in a grit blasted mold.

OBJECTS OF THE INVENTION

It is thus an object of this invention to provide a metallic coloredpolyolefin.

It is a further object of this invention to produce a metallic goldcolored polyolefin.

It is another object of this invention to produce a metallic Fort Knoxgold colored polyolefin.

It is yet a further object of this invention to produce a metalliccolored polyolefin product with a glossy finish.

It is yet a further object of this invention to produce a metalliccolored polyolefin product with a glossy finish in a grit blasted mold.

In accordance with this invention, it has been discovered that thefollowing compounds, when added in the appropriate concentrations,provide a metallic gold colored polyolefin composition:

a) olefin polymer,

b) mica-based gold pigment,

c) mica-based bronze pigment,

e) optionally, yellow pigment.

In accordance with another embodiment of this invention, a blend of oneor more olefin polymers with a plurality of mica-based pigments, carbonblack, and optionally, yellow pigment, is blended, extruded, andfinally, molded in a grit blasted mold under conditions sufficient toproduce a container having a glossy, metallic, gold color.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention provides a composition and a process to prepare ametallic, glossy, gold colored olefin polymer object in a grit blastedmold. More specifically, the metallic, glossy, gold colored olefinpolymer object is a metallic, glossy, Fort Knox gold colored polyolefinproduct.

CompositIon

The metallic, gold colored olefin polymer comprises combining pigmentswith an olefin polymer. At least three pigments, a mica-based goldpigment, a mica-based bronze pigment, and carbon black, are combinedwith the olefin polymer; a fourth pigment, a yellow pigment, optionally,can be added. Broad, intermediate, and preferred ranges of the olefinpolymer and four pigments in the final gold colored product are listedin the following table. The ranges are listed in approximate weightpercents of each component in the final composition. The broad rangeswere selected in order to obtain the desired coloration results; thepreferred ranges are preferred because they define a compositionpossessing the desired physical and chemical properties best suited toblend, extrude, and/or mold a metallic, glossy, gold colored polyolefinproduct. Too much mica-based gold pigment results in a product that istoo yellow in color; too little mica-based gold pigment creates a bronzecolored product. An excess of mica-based bronze pigment produces aproduct that is too orange and too little mica-based bronze pigmentresults in a yellow colored product. Too much carbon black creates adark gold, almost green, product; too little carbon black produces aproduct too light in gold color. An excess of yellow pigment results ina product that is too yellow in color.

                                      TABLE I                                     __________________________________________________________________________                      Intermediate                                                          Broad range,                                                                          range, approx.                                                                         Preferred range,                                   Ingredient                                                                              approx. wt. %                                                                         wt. %    approx wt. %                                       __________________________________________________________________________    Olefin polymer                                                                          95-98     97-97.9                                                                              97.4-97.7                                          Mica-based gold                                                                         0.5-4   1-2      1.5-1.9                                            pigment                                                                       Mica-based bronze                                                                       0.01-0.4                                                                              0.05-0.4 0.1-0.3                                            pigment                                                                       Carbon black                                                                            0.001-0.006                                                                           0.001-0.005                                                                            0.002-0.004                                        Yellow pigment                                                                          0-1     0.02-0.1 0.03-0.05                                          __________________________________________________________________________

As shown in Table I, the final metallic, glossy, gold colored olefinpolymer comprises pigment in the range of about 0.5 to about 3 weightpercent, based on the weight of the final colored polyolefin. The totalamount of pigment in the final product, as given above, is defined asthe pigment load or pigment loading factor.

The four pigments useful in accordance with this invention to produce ametallic, gold colored olefin polymer composition are commerciallyavailable products. The following tabulation gives possible suppliersand the trademarks for each of the pigment compounds.

The pigment suppliers and trademarks listed in Table II are merelyexamples of the pigments useful in this invention; the invention is notrestricted only to those pigments shown in Table II. As shown in TableII, the gold and bronze pigments are best described as anatase titaniumoxide (TiO₂) and/or iron oxide (Fe₂ O, or Fe₃ O₄.) coated mica, with aparticle size of less than about 200 microns. The pigment mica substratecan be described as platelet-shaped, transparent particles, which caninclude, for example, talc platelets; glass platelets; and various formsof mica, such as, for example, muscovite, white, biotite, phlogopite,related vermiculite, and synthetic micas. The carbon black is bestdescribed by the ASTM designation N110, according to ASTM method numberD1765-87a; however, other types of carbon black, such as any N100series, N200 series, N300 series, and mixtures thereof, according toASTM method number D1765-87a, can also be used. The yellow pigment canbe any type of translucent yellow pigment that can blend with apolyolefin.

                                      TABLE II                                    __________________________________________________________________________    Pigment                                                                       Compound                                                                              Supplier                                                                              Trademark                                                                              Reference                                            __________________________________________________________________________    Mica-based                                                                            EM Industries                                                                         Afflair ®                                                                          Fe.sub.2 O.sub.3 and anatase TiO.sub.2 coated                                 mica, particle                                       gold pigment                                                                          Inc.    Gold Pearl 300                                                                         size 10-60 microns, U.S. 4,435,220                   Mica-based                                                                            Mearl Corp.                                                                           Gold Sparkle                                                                           Fe.sub.2 O.sub.3 and anatase TiO.sub.2 coated                                 mica, particle                                       gold pigment             size 12-96 microns, U.S. 3,437,515,                                           U.S. 3,087,828, and U.S. 3,087,829                   Mica-based                                                                            Mearl Corp.                                                                           Brilliant Gold                                                                         Fe.sub.2 O.sub.3 and anatase TiO.sub.2 coated                                 mica, particle                                       gold pigment             size 6-96 microns, U.S. 3,437,515,                                            U.S. 3,087,828, and U.S. 3,087,829                   Mica-based                                                                            EM Industries,                                                                        Afflair ® Glitter                                                                  Fe.sub.2 O.sub.3 coated mica, particle size                                   10-150 microns                                       bronze pigment                                                                        Inc.    Bronze 530                                                    Mica-based                                                                            Mearl Corp.                                                                           Golden Bronze                                                                          Fe.sub.2 O.sub.3 and anatase TiO.sub.2 coated                                 mica, particle                                       bronze pigment           size 6-96 microns, U.S. 3,437,515,                                            U.S. 3,087,828, and U.S. 3,087,829                   Mica-based                                                                            Mearl Corp.                                                                           Super Bronze                                                                           Fe.sub.2 O.sub.3 coated mica, particle size 6-48                              microns,                                             bronze pigment           U.S. 3,437,515, U.S. 3,087,828, and                                           U.S. 3,087,829                                       Carbon black                                                                          Any carbon                                                                            No trademark,                                                                          Tint strength of about 115 to about 127**                    black supplier                                                                        but has ASTM                                                                  designation of                                                                series N100,                                                                  N200, N300 and                                                                mixtures thereof*                                             Yellow pigment                                                                        Ciba-Geigy                                                                            Irgazin ®                                                                          Red shade yellow organic pigment derived from                        Yellow 2RLT                                                                            tetrachloroisoindolinone                             Yellow pigment                                                                        Ciba-Geigy                                                                            Irgazin ®                                                                          Red shade yellow organic pigment derived from                        Yellow 3RLT                                                                            tetrachloroisoindolinone (more concentrated                                   than Irgazin ® Yellow 2RLT)                      Yellow pigment                                                                        Hilton-Davis                                                                          Trans-oxide ®                                                                      Pigment yellow #42 transparent yellow iron                           yellow   oxide                                                __________________________________________________________________________     *ASTM method number D176587a                                                  **Determined according to ASTM method number D326585a                    

The metallic, gold colored olefin polymer composition can be prepareddirectly as a final product with the appropriate weight percent amountsof each component, as earlier shown. However, it is also possible toproduce a polymer concentrate blend, which is a metallic, gold coloredolefin polymer with more concentrated pigment quantities. This metallic,gold colored olefin polymer concentrate blend can then be combined withan appropriate amount of additional colored or uncolored olefin polymerto produce a metallic, gold colored olefin polymer with a pigment loadin the final product in the range of about 0.5 to about 3 weightpercent.

The olefin polymer useful in this invention can be any olefinhomopolymer or copolymer with a density of greater than about 0.94 g/cc.Exemplary polyolefins include, but are not limited to, polyethylene,polypropylene and mixtures thereof. The polyethylene component of theinvention can be produced by any method known in the art. One method ofpolyethylene production uses a silica-supported chromium-oxide catalystsystem, such as described in U.S. Pat. No. 2,825,721 and U.S. Pat. No.2,951,816 by Hogan and Banks, which are herein incorporated byreference. Another method of polyethylene production uses a transitionmetal catalyst and relatively low temperatures and relatively lowpressures.

Polyethylene also can be produced by copolymerizing ethylene with one ormore higher alpha-olefin comonomers, preferably, with an alpha-olefinhaving about 3 to about 8 carbon atoms. The comonomer is normallypresent in a small percentage, i.e., an amount to maintain a polymerdensity of greater than about 0.94 g/cc. Usually, up to about 5 molepercent comonomer is present in the total monomer mixture. Examples ofethylene comonomers include, but are not limited to propylene, 1-butene,1-hexene, and mixtures thereof. 1-hexene, which produces butyl branches,is the presently preferred comonomer. Marlex® HHM 5502 ethylene-hexenecopolymer is the preferred polyolefin component of the invention.Marlex® resins are available from Phillips Chemical Company ofBartlesville, Okla.

The polypropylene component of the invention can be any crystallinepolypropylene, such as described in U.S. Pat. No. 4,376,851 by Hogan andBanks, which is herein incorporated by reference. The polypropylenecomponent can be produced by any method known in the art.

Processing

The metallic, gold tinted olefin polymer composition can be processed toform a glossy, metallic, gold product by sufficiently mixing thenecessary components and then extruding the composition into pellets forfuture use or into a parison for blow molding. The operating, orprocessing, parameters for the blending and extruding processes affectthe appearance, such as, for example, the gloss, texture, tint and hue,of the final metallic, glossy, gold product. The processing parametersespecially affect the gloss of the final product. Gloss, defined interms of this invention, refers to the reflective properties of thesurface of the tinted olefin polymer product; gloss does not necessarilyimply smoothness or color. When dealing with the composition of thisinvention, too much rough handling of the olefin and pigments in theform of, such as, for example, shear, grinding, and kneading, results ina loss of gloss in the final product. The olefin polymer and thepigments are dry blended in any type of dry blender, mixer, or tumbler.The blending process produces a dry blended product which is a fairlyevenly dispersed mixture of the olefin polymer and pigments. The speedof the blender should be in the range of about 700 to about 1000rotations per minute (rpm). Preferably, the blender speed is in therange of about 750 to about 900 rpm. Operating the blender at a higherrpm can cause a decrease in the gloss of the final product; too low of ablender speed does not always adequately mix the dry blend.

The dry blended product can then be extruded into pellets for future useor into a parison for blow molding. The maximum screw speed of theextruder is about 80 rpm. Preferably, the extruder screw speed is lessthan about 70 rpm. An excessively fast extruder screw speed results in adecrease of the gloss of the final olefin polymer product.

The opening or openings of the extruder have a size of greater thanabout 0.25 millimeters (mm). An opening of less than about 0.25 mmdecreases the gloss of the final product.

The operating temperature of the extruder is any temperature appropriateto extrude olefin polymers. The temperature can vary with differentolefin polymers. For example, with high density polyethylene,temperatures in the range of about 190° to about 235° C are appropriate.

EXAMPLES

A further understanding of the present invention and its advantages isprovided by reference to the following examples.

EXAMPLE 1 (Concentrate Blend)

A pigment concentrate blend in pellet form was made by dry blending thefollowing components in a Henschel mixer at slow speed (about 700 rpm);

    ______________________________________                                                               Approximate                                            Ingredient             Wt. %                                                  ______________________________________                                        High density polyethylene (HDPE) (1)                                                                 87.742                                                 Gold pearl pigment (2) 10.8                                                   Glitter bronze pigment (3)                                                                           1.2                                                    Irgazin yellow pigment (4)                                                                           0.24                                                   Carbon black (5)       0.018                                                  ______________________________________                                    

1. A polyethylene having a density of greater than about 0.94 sold underthe tradename of Marlex® HHM 5502 available from Phillips Chemical Co.,Bartlesville, Okla.

2. A bright, gold, inert, non-toxic, inorganic iron oxide (Fe₂ O₃) andan anatase type titanium oxide (TiO₂) coated mica pearl pigment, havinga 10 to 60 micron particle size, sold under the tradename Afflair® GoldPearl 300, available from E. M. Industries Inc., 5 Skyline Drive,Hawthorne, N.Y.

3. An inert, non-toxic, inorganic iron oxide (Fe₂ O₃) coated mica bronzepigment, having a 10 to 150 micron particle size, sold under thetradename Afflair® Glitter Bronze 530, available from E. M. IndustriesInc., 5 Skyline Drive, Hawthorne, N.Y.

4. An inorganic tetrachlorisoindolinone derived red shade yellowpigment, sold under the tradename Irgazin®Yellow 2RLT, available fromCiba-Geigy, Ardsley, N.Y.

5. A carbon black, designated as N110 according to ASTM D1765.

This dry blend of components was then fed to a 11/2 inch Johnsoncompound extruder, run at a screw speed of 80 rpm, a melt zonetemperature (zone 0) of 415° F., a feed zone temperature (zone 1) of420° F., transition zone temperature (zone 2) of 410° F., a meteringzone temperature (zone 3) of 410° F., a die zone temperature (zone 4) of410° F., and 300 psi pressure at the die inlet which is due to theplacement of 20 mesh, 40 mesh, and 60 mesh screens prior to the die (the20 and 40 mesh screens are used only for support of the 60 mesh screen).The strands from the Johnson compound extruder were then directedthrough a water bath and a rotating blade Cumberland model size 6,pelletizer to produce gold polyethylene pellets.

EXAMPLE 2 (Full Component Blend)

In a separate run the following ingredients were dry blended in the sameHenschel mixer, or tumbler, as in Example 1, at slow speed; his isidentified as full component blend:

    ______________________________________                                                               Approximate                                            Ingredient             Wt. %                                                  ______________________________________                                        High density polyethylene (HDPE) (1)                                                                 97.57                                                  Gold pearl pigment (2) 1.8                                                    Glitter bronze pigment (3)                                                                           0.2                                                    Irgazin yellow pigment (4)                                                                           0.04                                                   Carbon black (5)       0.003                                                  ______________________________________                                    

This dry blend of components was then fed to the same 11/2 inch Johnsoncompound extruder as in Example 1, run at a screw speed of 70 rpm, amelt zone temperature (zone 0) of 405° F., a feed zone temperature(zone 1) of 460° F., transition zone temperature (zone 2) of 450° F., ametering zone temperature (zone 3) of 450° F., a die zone temperature(zone 4) of 450° F., and 500 psi at the die inlet. The strands from theJohnson compound extruder were then directed through a water bath and arotating blade, Cumberland model size 6, pelletizer to produce goldpellets.

EXAMPLE 3 (Blow Molding)

The concentrate blend, with addition HDPE in a 5 to 1 letdown ratio(such as 5 pounds HDPE with 1 pound concentrate), and the full blendcomposition, in separate runs were fed to a Kautec model KEB 1continuous blow mold extruder, run at 65 rpm, zone 0 temperature 402°F., zone 1 temperature 380° F., zone 2 temperature 390° F., zone 3temperature 410° F., and a die face pressure of 900 psi (no screens werein front of the die). The extruder was connected to a quart oil cansplit grit blasted mold maintained at a temperature of 60° F. and a blowpressure of 2.25 bars (225 psi). This resulted in a glossy, metallic,Fort Knox gold pigment container having a 2% bottle pigment load.(Percent pigment load means the percent of pigment in the total finalresin volume found in the bottle).

The examples have been provided merely to illustrate the practice of theinvention and should not be read so as to limit the scope of theinvention or appended claims in any way. Reasonable variations andmodifications, not departing from the essence and spirit of theinvention, are contemplated to be within the scope of patent protectiondesired and sought.

That which is claimed is:
 1. A polyolefin container having a glossy,metallic gold color, made from the composition comprising:a) from about95 to about 98 weight percent olefin polymer, wherein said polymer has adensity of greater than or equal to about 0.94 g/cc; b) from about 0.5to about 4 weight percent mica-based gold pigment; c) from about 0.01 toabout 0.4 weight percent of mica-based bronze pigment; and d) from about0.001 to about 0.006 weight percent carbon black.
 2. A metallic goldcolored container according to claim 1 further comprising from greaterthan about 0 to about 1 weight percent yellow pigment.
 3. A containeraccording to claim 2 wherein said yellow pigment is a red shade yelloworganic pigment derived from tetrachlorisoindolinone.
 4. A containeraccording to claim 1 wherein said polymer is selected from the groupconsisting of homopolymers of ethylene, copolymers of ethylene andhigher alpha-olefins, and mixtures thereof.
 5. A container according toclaim 4 wherein said polymer is a copolymer of ethylene and 1-hexene andwherein said copolymer comprises 1-hexene in the range from about 0.05to about 5 mole percent.
 6. A container according to claim 1 whereinsaid gold pigment has a particle size in the range of about 10 to about60 microns.
 7. A container according to claim 1 wherein said mica-basedgold pigment is a mica-based gold pearl pigment.
 8. A containeraccording to claim 6 wherein said mica-based gold pearl pigment is iron(III) oxide and anatase titanium oxide on mica.
 9. A container accordingto claim 1, wherein said bronze pigment has a particle size in the rangeof about 10 to about 150 microns.
 10. A container according to claim 1wherein said mica-based bronze pigment is a mica-based glitter bronzepigment.
 11. A container according to claim 9 wherein said mica-basedglitter bronze pigment is iron (III) oxide on mica.
 12. A containeraccording to claim 1 wherein said carbon black is selected from thegroup consisting of N100 series, N200 series, N300 series, and mixturesthereof, according to ASTM method number D1765-87a.
 13. A containeraccording to claim 11 wherein said carbon black is N110 carbon black,according to ASTM method number D1765-87a.
 14. A container according toclaim 1 wherein said pigment loading factor is within the range of about1 to about 3 weight percent.
 15. A container according to claim 1wherein said container is blow-molded.
 16. A high density polyolefincontainer having a glossy, metallic gold color, made from thecomposition comprising:a) from about 95 to about 98 weight percentpolymer of ethylene and 1-hexene, wherein said polymer has a density ofgreater than or equal to about 0.94 g/cc; b) from about 0.5 to about 4weight percent mica-based gold pigment, wherein said mica-based goldpigment comprises anatase TiO₂ and Fe₂ O₃, coated mica and wherein saidmica-based gold pigment has a particle size in the range from about 6 toabout 96 microns; c) from about 0.01 to about 0.4 weight percentmica-based bronze pigment, wherein said mica-based bronze pigmentcomprises mica coated with oxides selected from the group consisting ofanatase TiO₂, Fe₂ O₃, and mixtures thereof and wherein said mica-basedbronze pigment has a particle size in the range from about 6 to about150 microns; d) from about 0.001 to about 0.006 weight percent N110carbon black, as designated according to ASTM method D1765-87a; and e)from greater than about 0 to about 1 weight percent yellow pigment,wherein said yellow pigment can blend with said polymer.
 17. A containeraccording to claim 16 wherein said polymer comprises 1-hexene in therange from about 0.05 to about 5 mole percent.